White Rot Fungus Used to Remediate Dioxin-Polluted Soil

Bioremediation using white rot fungus has now become a viable option for treating dioxin-contaminated soil, thanks to a new method jointly developed by a corporate research team led by Taisei Corp., a major Japanese construction company. This fungus produces enzymes capable of degrading lignin, an organic compound integral to plant cell walls. Practical application of the method is expected by the end of 2006, facilitating Taisei's plans to expand its soil remediation business.

Remediation of dioxin-contaminated soil generally involves excavation of the contaminated soil and its disposal as industrial waste, or thermal desorption through incineration. Biological remediation, on the other hand, is usually time-consuming and not efficient enough to be commercially viable. In the newly developed technology, lignin-degrading enzymes produced by white rot fungi are extracted and added in liquid form to the dioxin-contaminated soil under conditions optimal for increased microbial activity.

White rot fungus is a common fungus that causes wood decay; it excretes lignin-degrading enzymes with highly active oxidizing properties that can decompose various organic compounds. This unique property of white rot fungi is attracting attention in many fields relating to environmental remediation methods for cleaning up a wide range of organic contaminants, including toxic pesticides (such as DDT), PCBs and dioxin.